Let's consider a puzzle that has been made using a computer program. If you are a reasonably experienced solver, you might wish to tackle it. You will soon discover that making a start is difficult. There are no cells in which to place a number using straightforward techniques. I'll show you what to do. Look at box one (upper-left 3x3). There is no 6 in this box, but there are 6s in columns one and three. So, in box one, a 6 can only go in column two, but there are two possible cells. Next, let's look at 1. In box four (centre-left 3x3) and box seven (bottom-left 3x3) there are no 1s. But there are 1s in rows four, six, seven and nine. In box four, a 1 can only go in row five, and in box seven a 1 can only go in row eight. This means that columns one and three cannot be used for a 1 in box one. The two cells of column two in box one will be occupied by a 1 and a 6. Using this information, you can find the cell that contains an 8 in box one. That's right - column one, row two. Now, all of the 8s can be placed easily. Once you have discovered how to solve this problem, the puzzle presents no other difficulties.

Can you really say that you enjoy solving this kind of puzzle? I never can. Computer-generated Sudoku puzzles are lacking a vital ingredient that makes puzzles enjoyable - the sense of communication between solver and author. The best Sudoku make you concentrate, but aren't stressful. They are absorbing, never boring.

That was said regarding this puzzle:

Anyway, here's puzzle 70 from issue 7 of Sudoku Magazine, containing Nikoli puzzles:

- Code: Select all
`9 ¦ 6¦ 7`

3 ¦1 ¦ 5

5¦ ¦3

---+---+---

5 ¦4 2¦ 3

¦ ¦

7 ¦8 9¦ 5

---+---+---

4¦ ¦8

6 ¦ 7¦ 9

1 ¦2 ¦ 6

As far as I can tell, to solve this puzzle you need to find a hidden pair in box 2 (which is easiest to find by first finding another hidden pair in that box), find another pair, in row 4 (again, easiest if you found the first pair), use the second pair to find another pair inbox 8, and from that pair and the first pair, place a number in box 8. After all that, everything in the puzzle is trivial. This is exactly what they accuse CG puzzles of being like (though they never are, in my experience). So do the handmade puzzles have anything to offer?